Induced-current medical instrument with condenser



Aug. 21, 1925. 1,681,708

K. MURAKOSHI INDUCED CURRENT MEDICAL INSTRUMENT WITH CONDENSER Filed April '7, 1923 MNK A Q Y v l 15 16 K0 OBOMUJULZEOSILL,

Patented Aug. 21, 1928.

UNITED STATES KOGORO MURAKOSHI, OF TOKYO PREFECTURE, JAPAN.

1,681,705; PATENT OFFICE,

mnoorin-ounnnurmnnicnn INSTRUMENT WITH CONDENSER.

Application filed April 7, 1923, Serial No. 630,663, and in Japan June 13, 1921;

This invention relates to an induced current medical instrument consisting of an electric condenser inserted in series in the secondary coil of an induction" coil; the principal object is to obtain an effective treatment without inflicting pain and providing a sufiicient stimulus and contraction to nerve tissues without pain.

In the accompanying drawings,

taken from the device of ordinary interrupted induced current without a condenser and that taken from the device of the invention provided with a condenser. Fig. 2 is a diagram illustrating the principle of the invention and Fig. 3 is a perspective view of the medical instrument of the invention.

Allexisting induced current medical instruments have the defect of producing'eleo tric current of a longer duration than is actually required for contracting patients muscles, while the contraction of the muscles requires only a current of very short duration or instantaneous interrupted current, and current in excess not only circulates through the body to no purpose, but it generally gives stimulus to sensory nerves, giving such an unpleasant stinging pain as will induce patients to gradually have an aversion to this kind of treatment, and it can not be doubted, therefore, that they soon come to feel some shock at every treatment, which is a great defect in treatment of this kind. The kind of such bad current is shown as A curve in Fig. 1, while the ideal curve of no pain 1s shown as B curve in the same. drawing. These curves are made of curves actually taken by an oscillograph'.

In the present invention, however, this defeet has been eliminated, where an electric condenser is inserted in series in the secondary coil and only an ideal current, that is, a current of a very short duration required for contraction of muscles is produced, and no 5 more pain or shock is felt by the patient using this apparatus. Thus, only with such apparatus can a patient get rid of the idea that the induced current remedy is painful, and believe that the deseased nerve tissues which are paralyzed can be made to return to their normal functions and be moved-at will. The capacity of the condenser used in the apparatus must of course correspond to a certain definite coil.

In Fig. 2, P and S are induction coils; G the condenser; K is a switch and a is a con- Fig. 1 shows diagrams of curve of current tact. The primary coil (P) and the second-- ary coil (S) may be coiled round a frame 3 which has an iron core within; It is better to use a wire of a'comparatively large diameter, say, of gauge No. 25 to increase the quantity of current; the ratio of the primary to the secondary coil may he, say, 10 to 20. lVhen a cell or a source of electricity is connected with the primary coil (P) and the current is put 1n circulation, that is, the circuit is closed by means of a switch, an induced current is produced in the secondary coil (S). By the proper insertions of core, the lines of magnetic force can be modified; by the proper use of a copper tube inserted round the core, the sensitiveness of the current on the secondary coil resulting from the eddy current produced in the tube can be modified; it can also be modified either by increasing or decreasing the number of divisions of the secondary coil: For example, it is divided into five as shown in Figure 2.

When a switch K is connected with a. contact (a) the condenser (C) is short circuited, and when it is not connected with (a), the condenser will come into circuit and will be connected with the secondary coil in series.

Fig. 3 shows a perspective outer view of the instrument according to the invention,

the electric connection being shown by broken lines. In the figures, l is a switch of the primary circuit; 2 is the cell; 3 is terminal screw of 1; 4 is a resistance; 5 is a regulator; 6 is a platinum interrupter; 7 is an adjusting screw of the interrupter; 8 is a set screw of a vibrating tongue; 9 isthe vibrating tongue. Thus the primary circuit is composed of the parts numbered from 1 to 9 and the coil P.

The secondary circuit is composed of the tollowing parts; the coil S; terminals 10, 11, 12; a contact a; a switch a contact 14; handles 15 and 16; codes 17 and 18. The cable 18 is always connected to the terminal 12 while the other cable 17 may be connected either to the terminal 10 or 11 according to whether three or five divisions of'the secondary coil S are taken into the secondary circuit. The strength of the current can be finely adjusted by adjusting the resistance 4 in the primary circuit and also changing the connection of the cable 17 either to the terminal 10 or 11.

In this invention some slight change in the diameter of the wire or the ratio'of the primary to the secondary coil may be made in so far as it does not deviate from the spirit of the invention.

Having now particularly described the nature of the invention, I declare What I claim is:

1. In an electro-therapeutic apparatus, an induction coilincluding primary and sec ondary windings, and an applicator permanently connected with one terminal of the and intermediate portion of the secondary winding, and a second applicator selectively engageable with the electrical connectors.

2. An electro-therapeutic apparatus as claimed in claim 1 characterized by the provision of a primary circuit associated with the primary winding and including a variable resistance for regulating the current passing through the primary winding.

In testimony whereof he affixes his signature.

KOGORQ MURAKOSHL: 

